Neither higher doses of anti-clotting drugs nor filters inserted in the vena cava are guaranteed to help prevent venous thromboembolism (VTE) during bariatric surgery, a review of the literature suggests.
A systematic review and meta-analysis was unable to show that an increased dosage of these medications can prevent VTE in bariatric surgery patients, reported Daniel J. Brotman, MD, and colleagues of Johns Hopkins University, and colleagues
This finding is "consistent with current American College of Chest Physicians guidelines, which do not distinguish between patients undergoing bariatric surgery and those undergoing other types of abdominal surgery," the authors wrote in the study published 0nline by JAMA Surgery.
The literature review also came up empty regarding support for the prophylactic use of filters placed in the inferior vena cava, with a trend toward higher rates of deep vein thrombosis (DVT) and mortality associated with patients receiving filters.
A common perception is that morbidly obese patients "may require more aggressive VTE prophylaxis than other surgical patients," the investigators noted. But the optimal approach for reducing the risk of VTE remains unclear.
Researchers therefore scoured the literature and identified eight primary studies that evaluated various pharmacotherapy strategies aimed at preventing VTE, which includes DVT and pulmonary embolism (PE), in bariatric patients undergoing surgery.
The literature search also turned up five viable studies examining filter placement for prophylaxis of VTE.
The filters that were used varied according to physician and practice preference. They included these retrievable filters: Gunther Tulip, Bard Recovery, OptEase, Cook Celect, and Bard G2, and nonretrievable filters such as the Greenfield Stainless Steel, Simon Nitinol, and TrapEase.
The authors found only one study that included the filter retrieval rate: 92%.
Also, filter use was sometimes accompanied by drug therapy, such as enoxaparin, heparin, or warfarin.
The authors found no randomized clinical trials addressing the comparative effectiveness of different interventions to prevent VTE among patients undergoing bariatric surgery so all the studies were observational in nature.